The present invention relates to a vehicle power transmission device.
A vehicle power transmission device is known in the art that includes a continuously variable transmission unit, a differential mechanism (differential gear) and the like, and is structured so as to scoop up a lubricating oil by a differential ring gear (final driven gear) rotating together with wheels and to supply the scooped-up lubricating oil to a predetermined element to be lubricated by gravity (e.g., see Japanese Patent Application Publication No. JP-A-2004-183714). Although an oil pump cannot be operated during towing of a vehicle, the vehicle power transmission device mounted on the vehicle enables a relatively large amount of lubricating oil to be reliably guided to an oil receiver by gears rotating with the wheels and by gravity, whereby an element to be lubricated can be lubricated.
In another vehicle power transmission device known in the art, a lower part of a power transmission mechanism chamber in a housing is partitioned by a weir into a bottomed differential chamber accommodating a differential mechanism and an oil pan chamber communicating with an oil pan (e.g., see Japanese Patent Application Publication No. JP-A-2004-36633). In this vehicle power transmission device, an opening extending in the direction perpendicular to an axial direction of the differential mechanism is formed in the weir partitioning the differential chamber and the oil pan chamber. The differential chamber and the oil pan chamber communicate with each other through this opening.
Further, Japanese Patent Application Publication No. JP-A-2004-36633 describes that a one-way valve is provided in the opening formed in the weir in order to prevent lubricating oil from flowing out of the oil pan chamber into the differential chamber (e.g., see FIG. 6 in JP-A-2004-36633).